Utility-scale solar generation overtook natural gas generation in the California Independent System Operator’s footprint over the first five months of 2026, according to a Tuesday report from the Energy Information Administration.
From January through May, solar generation in CAISO increased 21% compared with the same period in 2024, while natural gas generation decreased 60%, EIA found.
“In CAISO, utility-scale solar generated more electricity than natural gas on a daily basis on 82% of days in the first five months of 2026, up from 21% in 2024 and 2025,” the agency said.
EIA found that between April 2024 and April 2026, utility-scale solar generating capacity grew 19%, to 25 GW, and battery storage capacity grew 79%, to 16 GW.
At the same time, natural gas capacity remained “nearly unchanged” at 29 GW, EIA said. “Total net capacity increased by 14% (11 GW) over this period.”
However, despite this increasing generation from solar and batteries — and a 7% increase in demand — “there was a 19% decrease in net generation as electricity imports from nearby systems doubled in CAISO,” EIA said. “The increase in imports was driven by relatively inexpensive electricity generation coming online and available for import.”
Much of the imported energy comes from renewables. “Hydroelectric power imports from the Pacific Northwest increased as the drought there subsided, and CAISO began importing from the new SunZia wind project in New Mexico starting April of this year,” EIA added.
The 3.65 GW SunZia project is the largest wind farm in the U.S. It began delivering electricity in a testing phase in April but is set to begin commercial operations this month.
“Most of the electricity generated at SunZia will be exported to Arizona and to Southern California,” EIA said in a Friday report about the project. Its initial exports to CAISO have begun showing up in the ISO’s generation mix: “On May 15, 2026, CAISO reported 7,122 MW of hourly wind generation, which is 20% higher than the previous annual record of 5,922 MW in 2024,” EIA said.